Process of bleaching and decolorizing hair, animal fibers, and fur skins



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FIP8309 onion TEXHLES & FIBERS,

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Patented Nov. 1, 1932 UNI 1i;

PATENT OFFICE STANLEY S. GROGGINS, OF BROOKLYN, NEW YORK, ASSIGNOR TO COLOXIDE PATENTS CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK PROCESS OF BLEAOHING AND DECOLORIZING HAIR, ANIMAL FIBERS, AND FUR SKINS No Drawing.

1 be used advantageously in the bleaching of fur skins without impairing the strength, lustre or texture of the articles bleached in accordance with the principles of the present invention.

According to my invention, I provide a method of bleaching hair, animal fibers ant fur skins which comprises treating these bodies with an oxidizing agent in the presence of colloidal bodies. The invention further consists in the method described, wherein the bleaching or oxidizing agents are preferably peroxides, perborates, or persulfates, either alone or in any desired combination in a solution of suitable strength. The invention further consists in regulating the hydrogen ion concentration of the oxidizing solution so that the liberation of nascent oxygen is effected in a steady and regulated manner to the end thatthe bleaching or decolorizing is accomplished without injury to the hair, animal fibers, or fur skin.

The invention further comprises the utilization of the oxidizing agents in the presence of colloidal substances which.act as catalysts in this oxidation or bleaching process. I prefer to use colorless colloids, such as silicate of soda, silica gels, starch, and aluminum compounds, particularly in the form of gelatinous hydroxides. One or more of the colloidal bodies may be used in combination. Thus silicate of soda may be used in combination with an aluminum alum to reduce or neutralize the alkalinity of the former and to throw out the aluminum compound as a l colloidal hydroxide. Thus the addition of the alum maintains the aqueous bleaching solution approximately neutral. These colloids permit carrying out bleaching or oxidizing operations with lower dilutions of oxidizing agent in an expeditious and economical man- Application filed. January 16, 1932. Serial No. 587,165.

ner, for there is a maximum utilization of the available oxygen that is present in the oxidation bath. This phenomenon is attributed to the fact that such colloids enlarge the active surface area of oxidation several thousand fold and inhibit the escape of oxygen from soluton.

Another embodiment of my invention comprises a preliminary treatment of the hair, animal fibers, or fur skins with such colloids and subsequently applying the oxidizing agent or agents in a separate step after a large proportion of the colloidal suspension has been removed. The obvious advantage in making this extra step is the possibility of reusing the colloidal suspension in subsequent operations. Since, however, these colloids are quite inexpensive and since they do not generally consume the oxygen liberated from the peroxides, perborates, and persulfates that are used, it is wholly feasible to conduct the bleaching or oxidizing operation in one step.

I am aware that bleaching and oxidizing processes utilizing ferrous salts or other metals capable of existing in two valences have long been carried out. Although such ferrous compounds have been found advantageous in the oxidation of numerous organic compounds, they are not particularly suitable for the bleaching of human hair, animal fibers or fur skins, since they impart characteristic colors to the fibrous material being treated. Thus, in the bleaching of fur skins, ferrous compounds deposit a brown ferric compound, and cuprous salts deposit a blue or green cupric compound on the fur skins being treated during the course of the oxidation process. This pigmentation, of course, limits the practical application of such metal compounds in the industrial arts. The use of ous salts, for example ferrous sulfate, involves not only a waste of available oxygen, but also involves a precipitous initial oxidizing action which impairs the fibrous material.

The bleaching of textiles and fabrics can give no valuable information as regards the treatment of fur skins for the reason that fur skins comprise a leather portion as well as hair and each reacts differently to various oxidizing or reducing solutions. It is necessary therefore to investigate and ascertain the conditions which will be suitable for bleaching the hairs of the fur skin without impairing or damaging either the hair or the leather comprising the same.

In the accompanying specification I shall describe illustrative embodiments of the methods of the present invention as applied more particularly to the bleaching of hair, animal fibers and fur skins. It is, however, to be clearly understood that my invention is not limited to the specific embodiments thereof herein described for purposes of illustration only. By means of the present invention I am enabled to decolorize or bleach dark colored fur skins without weakening or destroying the leather of the skins and without weakening or impairing the natural texture and strength of the hair. Skins bleached or decolorized in accordance with the principles of the present invention may thereafter be very readily and expeditiously dyed the same colors, light or otherwise, as can at present he applied with success only to natural white or light colored furs. Furthermore, the entire combined operation of bleaching or decolorizing the skins and thereafter dyeing them in accordance with the principles of the present invention requires only as much, or even less, time than the ordinary fur dyeing process. Furthermore, the resultant bleached or decolorized skins and the subsequently dyed skins are characterized by the leather of such skins coming out of the process in sound condition as to strength and texture, and by the hair likewise coming out of the process in sound condition as to strength, texture, and lustre. In fact, furs treated in accordance with the present invention come out of the process, after the combined bleaching or deeolorizing and subsequent dyeing operations, affected less, or only as much, as furs which have been merely dyed by the dyeing methods hitherto customarily employed.

The following are specific examples of one mode of applying the method of the present invention, it being understood, however, that the following description is given merely by way of illustration only and that the process is not limited to the specific details of the following illustrative examples.

Example J.Clean, dark gray rabbit skins are placed into a colloidal starch suspension containing from 1 to 5 parts of starch per 100 parts of water. Hydrogen peroxide is then added, the quantity of which may vary from 10 per cent to 100 per cent by volume of a three (3) per cent solution of hydrogen peroxide. The hydrogen ion concentration in this case is regulated by the intermittent addition of ammonium hydroxide so that the available oxygen is liberated in a regulated manner. I prefer that the temperature at which the bleaching or oxidizing operation is carried out shall be between 20 and 35 C. The skins are subjected to the action of the bleaching or decolorizing agent until they have been sufiiciently decolorized. The bleached or decolorized skins are then rinsed and can, if desired, be dyed directly in accordance with any of the well known or desirable processes employed for dyeing furs or the like. I may, however, subject the bleached or decolorized skins to the usual dyeing operations of washing and mordanting, and then dyeing the washed and mordanted skins in accordance with the practice hitherto generally employed for dyeing furs.

Ewample 2.Clean brown mouflions are placed in a colloidal suspension consisting of two parts of technical. silicate of soda and two parts of potassium aluminum sulfate per 100 parts of water. Hydrogen peroxide and ammonium persulfate are added, maintaining the hydrogen ion concentration first above pH 7 and finally below this point. After the skins have been sufliciently bleached, which operation usually takes from two to six hours, the skins are thoroughly rinsed and washed to remove the colorless colloidal suspension. The bleached fur skins may then be used or dyed in any manner like natural light colored skins.

The present invention may also he applied with particular success to the treatment of dark colored animal fibers, particularly dark colored hair, and fur skins carrying the same, to render the same suitable for felting operations and to derive from the same a feltable fiber of a light color very suitable for dyeing and for felting into a felted fabric.

Before describing in detail the aforesaid illustrative embodiments of the present invention, it may be desirable briefly to point out certain disadvantages of the prior art so far as the same relates to the field of the present invention. Hitherto it has been proposed, for example, to carrot animal fibers, such as fur skins and the like or the hair of such skins, to render the same suitable for felting operations, by treating such skins or the hair of the same with an acid solution of nitrate of mercury. This treatment, if used by itself for the entire carroting operation, tends to weaken and otherwise hurt the hairs or equivalent fibers.

Furthermore, where it is desired to obtain a light colored mass of feltable hairs or other animal fibers, if the hair is bleached first, the bleaching operation generally tends to weaken the hair to such an extent that the subsequent carroting operation, tending further to weaken the hair, would tend often to render the same quite unfit for the subsequent felting operation. It has, therefore, not been feasible to make a light colored mechanically desirable feltable fiber from a dark colored 8. BtEACHlNG 6i DYEENG; FLUlll lfiEATlllElll & Ci'iElviiCid WEQUIFL CATEQN OF TEXTILES 6L FIBERS,

skin by the usual bleaching and carroting operations.

On the other hand, if the hair or equivalent animal fibers are first carroted, as by means of the treatment with the acid solution of nitrate of mercury referred to above, this treatment would tend to render the subsequent bleaching operation imperfect and otherwise quite unsatisfactory. In any event, both the carroting and the bleaching operations are hitherto conducted, in what ever order they have been carried out, would both singly and conjointly tend to considerably weaken and otherwise impair the structure and appearance, as well as the felting qualities of the fur, hair or other fibers to which the treatments of the prior art might be applied.

.l have discovered a new method of can roting or treating fur skins, hair and other animal fibers to render the same suitable for subsequent felting operations. My new carroting process is characterized by the fact that it does not substantially hurt the fur, hair or other fibers treated in accordance with such process. The carroting operation of the present invention may moreover be very effectively combined with a bleaching operation whereby dark colored skins or the hair thereof may be ultimately obtained in a condition ideally suited for felting or already felted in a very light color, in which condition the feltable mass or the felted product is admirably suited for dyeing any light or other suitable color. In one of its forms, in fact, my present invention comprehends a preliminary and partial carroting operation followed by a bleachin operation which at the same tme completes the carroting operation and thus yields a bleached fiber admirably suited for felting.

Referring now to the aforesaid illustrative embodiments of the methods of the present invention, 1 take first any suitable fur skin or the hair of such skin, or any other suitable animal fiber which it is desired to convert into a feltable fiber. Preferably, I treat a fiber which is dark and which I desire to bleach into a light colored readily feltable fiber. The following is a specific example of another mode of applying the method of the present invention, it being understood, however, that the following description is given merely by way of illustration and that the process is not limited to the specific details of the following illustrative example.

Eammple 3.Clean, dark colored rabbit skins are imersed in an acid solution of mercury nitrate in an amount suflicient only to partially carrot such skins or animal fibres. For example, only one-half to two-thirds of the acid solution of nitrate of mercury is employed, so that the carroting operation at this stage is only partially completed.

The partially carroted skins or other animal fibers are then rinsed and thoroughly hydro-extracted. The skins or fibers are then immersed in an aqueous colloidal suspension of starch or silicate of soda containing from one to five parts of colloid per parts of 7 water. Hydrogen peroxide and ammonium persulfate are then added, adjusting the hydrogen ion concentration if necessary to regulate the pH first on the acid and finally on the alkaline side. In place of hydrogen peroxide, sodium peroxide or sodium perborate may be used; these compounds yielding hydrogen peroxide in the presence of dilute acids. The amount of hydrogen peroxide used may vary from about five to one hundred per cent by volume of a three per cent solution of hydrogen peroxide. I prefer that the temperature at which the bleaching or decolorizing operation is carried out shall be tween 20 and 35 C.

The skins or hair are subject to the action of the bleaching and carroting agent until hey have been sufiiciently decolorized. The bleached and now completely carroted skins or hair are now rinsed and can, if desired, be dyed directly in accordance with any of the well known or desirable processes employed for dyeing furs or the like. I may, however, subject the bleached or decolorized fur skins or hair to the usual dyeing operation of washing and mordanting, and then dyeing the washed and mordanted skins or hair in accordance with the practice hitherito generally employed for dyeing furs and iair.

The advantages of the foregoing process are numerous and of 'great practical importance, and may be briefly summorized as follows: In the first place, the process enables dark colored fur skins or the like to be bleached or decolorized to a white or very light color without destroying or even weakeningtheleatherofthe skins, and without impairing the strength, texture or lustre of the hair of such skins. The process is at the same time very simple, convenient and economical to practice, and while enabling the desired decolorizing or bleaching operation to be conducted safely and with due regard to the strength and texture of the final product, serves in a simple and inexplicable way to accelerate the bleaching or decolorizing operation.

Further advantage of the foregoing embodiments of the processes of the present invention may be briefly summarized as follows:

By combining the bleaching operation with the completion of the carroting operation, as above described, a ready control of the carroting operation of the bleaching operation is rendered possible and a final product obtained which is remarkable for its strength, texture, and felting-qualities.

It may here be stated that under certain conditions the combined bleaching and car roting operation by means of a non-metallic carroting agent may be carried out first, after which the carroting operation may be completed by regulating the amount and length of time of treatment with the acid solution of nitrate of mercury or its equivalent. It may here also be stated that the bleaching operation may be carried out with complete success on fibers or even felts already completely carroted by treatment with an acid solution of nitrate of mercury, or equivalent reagent. In fact, the bleaching operation may be carried out with remarkable success on shaped felted bodies such as hat bodies, after the carroting operation has been completed. Or else such fibers, masses of felt or shaped felted bodies, may first be bleached and partially carroted and thereafter carroted to completion as already indicated above. Other advantages of the methods of the present invention will readily occur to those skilled in the art to which the present invention relates.

hat I claim as my invention is:

l. The method of bleaching fur skins which comprises treating the same with an approximately neutral aqueous solution consisting of hydrogen peroxide and a colloid selected from the group consisting of starch, silicate of soda and aluminum hydroxide, at 2035 G.

2. The method of bleaching fur skins which comprises treating the same with an approximately neutral aqueous solution consisting of hydrogen peroxide and colloidal silicate of soda at 20-35 C.

3. The method of bleaching fur skins which comprises treating the same with an approximately neutral aqueous solution consisting of hydrogen peroxide and a mixture of colloidal aluminum hydroxide and silicate of soda at 20-35 C.

4. The method of bleaching fur skins which comprises treating the same with an approximately neutral aqueous solution consisting of hydrogen peroxide and colloidal starch at 20-35 C.

Dated, this 5th day of January, 1932.

STANLEY S. GROGGINS. 

